This presumed domain is found in the RTC4 protein from yeasts. In Saccharomyces cerevisiae, Cdc13 binds telomeric DNA to recruit telomerase and to "cap" chromosome ends. RTC4 was identified in a screen to identify novel proteins and pathways that cap telomeres, or that respond to uncapped telomeres [1]. This domain is also found in proteins that contain a DNA-binding myb domain.

1: A genomewide suppressor and enhancer analysis of cdc13-1 reveals varied cellular processes influencing telomere capping in Saccharomyces cerevisiae. Addinall SG, Downey M, Yu M, Zubko MK, Dewar J, Leake A, Hallinan J, Shaw O, James K, Wilkinson DJ, Wipat A, Durocher D, Lydall D; Genetics. 2008;180:2251-2266. PMID:18845848